Method and apparatus for applying a coating to a tubular member

ABSTRACT

A METHOD AND APPARATUS FOR APPLYING A COATING UNDER COMPRESSION TO A TUBULAR MEMBER PERMITS IMPROVED ADHESION OF THE COATING TO THE TUBULAR MEMBER WITH IMPROVED CONSISTENCY AND STRENGTH OF THE APPLIED COATING,   D R A W I N G

June 194, 1973 1. B. MALLARD v 3,740,291

METHOD AND APPARATUS FOR APPLYING A COATING TO A TUBULAR MEMBER INI/ ENTOR nous' willow f Malflaewl ATTORNE YS June 19, 1973 Filed Jan. 20,1971 J. B. MALLARD METHOD ANI) APPARATUS FOR APPLYING A COATING TO ATUBULAR MEMBER 3 Sheets-Sheet 2 ATTORNEYS June 19,l 1973 J. B. MALLARD3,740,291

METHOD AND APPARATUS FOR APPLYING A COATING To A TUBULAR MEMBER FiledJan. 20, 1971 3 Sheets-Sheet 3 Y nu!! who@ MAMMA ff T'TRN YX UnitedStates Patent O 3,740,291 METHOD AND APPARATUS FOR APPLYING A COATING TA TUBULAR MEMBER .lames B. Mallard, 609 Ripple Creek, Houston, Tex.77027 Continuation-impart of abandoned application Ser. No.

761,151, Sept. 20, 1968. This application Jan. 20, 1971,

Ser. No. 108,020

Int. Cl. B32b .i1/06; B651: 81 00 U.S. Cl. 156--392 4 Claims ABSTRACT 0FTHE DISCLOSURE A method and apparatus for applying a coating undercompression to a tubular member permits improved adhesion of the coatingto the tubular member with improved consistency and strength of theapplied coating.

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-partof my copending application Ser. No. 761,151, tiled Sept. 20, 1968 forMethod and Apparatus for Applying a Coating Under Compression to aTubular Member now abandoned.

BACKGROUND OF THE INVENTION (l) Field of the invention The presentinvention relates to methods and apparatus for applying a coating to atubular member.

(2) Description of the prior art In the prior art methods and apparatusfor coating tubular members, adhesion of the coating to the member wasdiicult to obtain. Consistency in the mixture of the ingredients of thecoating often varied during application, decreasing the strength of theapplied coating and making the exterior of the coating uneven and rough.Further, when the tubular member to be coated had a protective exteriorcoating, the ingredients of the coating often damaged the protectivecoating during application and failed to adhere to such protectivecoating. The coated tubular members had to be cured after coating priorto installation in order to allow the applied coating to harden. Duringinstallation, the uneven coating of the tubular members would oftendamage the installation equipment, particularly the rollers supportingthe member in such equipment.

SUMMARY OF THE INVENTION Briefly, the present invention provides a newand improved method and apparatus for applying a coating to a tubularmember. In the method and apparatus of the present invention, thetubular member is rotated and simultaneously moved longitudinally withrespect to a placing head. A coating material is deposited or applieddirectly to the tubular member in such placing head while a strip ofcovering or wrapping material which is held under selectively controlledamounts of tension on a feed roll is conducted to such placing head andcompressively wrapped with the deposited coating material against therotating tubular member to form a covered coating layer on the tubularmember. The tension in the wrapping material and the compressivewrapping of the coating material with the tubular member permit adhesionof the coating to the tubular member, and allow application of thecoating material over a protective coating on the exterior of thetubular member with reduced damage to such protective coating. Thecoating material is vibrated and compacted While in the placing head sothat the coating material is rm and substantially uniform in compositionwhen compressively wrapped to the tubular mem- ICC ber. The uniformcomposition of the coating material forms a consistent density andabsorption in the coating material, eliminating porosity in the coatingand unevenly applied coatings and reinforcing Wire mesh may becompressively wrapped by the placing head into the coating materialinteriorly of the Wrapping material to further strengthen the coatingmaterial. The method and apparatus of the present invention providescontinuous coating operations by abutting an end of a second tubularmember with the end of a first tubular member as coating of the firsttubular member nears completion and thereafter coating the abutting endsof such tubular members. Subsequently, the coating is removed from aportion of such abutting ends to provide access for ywelding orotherwise connecting the tubular members when such members are beinginstalled or put into place for use.

The dry constituents of the coating material being applied are conveyedto a mixing station adjacent the placing head ywhere liquid is added tothe dry constituents and the coating material is formed, so that onlyrequired amounts of the coating material are mixed, to reduce waste ofthe coating material should coating operations be unexpectedlyinterrupted. When the coating material is concrete, larger aggregate maybe used with the method and apparatus of the present invention, reducingthe amount of cement required to achieve the desired strength in theapplied coating. The coated pipe may be stacked and stored after coatingWithout requiring curing, permitting earlier hardening and use of thecoated pipe.

It is an object of the present invention to provide a new and improvedmethod and apparatus for applying a coating to a tubular member.

It is an object of the present invention to provide a new and improvedmethod and apparatus for depositing a coating material onto the tubularmember and compressively wrapping the coating against the tubular memberwith a wrapping material to provide a coating under compression for suchtubular member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the coatingapparatus of the present invention;

FIG. 2 is an isometric view of a tubular member with a compressivecoating being applied in accordance with the present invention;

FIG. 3 is an isometric view of the placing head of the apparatus andmethod of the present invention;

FIG. 4 is a cross-sectional view of the placing head of FIG. 3;

FIG. 4A is a cross-sectional View taken along the line 4A-4A of FIG. 4;

FIG. 5 is a cross-sectional view taken along the lines 5-5 of FIG. 1;and

FIG. 6 is a cross-sectional view taken along the lines 6 6 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter Adesignates generally the coating apparatus of the present inventionperforming the method of the present invention and compressivelyapplying a coating material, such as for example concrete or the like,to a tubular member T which may be a steel or iron pipe or tube or thelike, having a corrosion protective coating or other suitable coating ifdesired.

The apparatus A (FIG. l) includes a conveyor system C which rotates thetubular member T While simultaneously moving such tubular member Tlongitudinally past a platform P with which a placing head H is mounted.

A coating material conveyor system S conveys the dry constituents of thecoating material to a mixing chamber M wherein water or other suitablefluid is added to the dry constituents of the coating material to formthe coating material 81. A feed channel L conveys the coating material81 from the mixing chamber M to the placing head H where such coatingmaterial is deposited onto the tubular member T. A plurality of storagereels R have mounted therewith rolls of a wrapping or covering material61, which may be paper, plastic, impregnated paper or other suitablematerial, and a roll of reinforcing wire mesh 62, respectively. TheWrapping material `61 and the reinforcing wire mesh 62 are stored on thereels R and conducted therefrom under tension, in a manner to be set outhereinbelow, to the placing head H wherein the coating material 81 beingdeposited onto the rotating tubular member T is compressively wrappedagainst such rotating tubular member T with a strip of the wrappingmaterial 61, and the reinforcing wire mesh 62 is compressively wrappedinto the deposited coating material 81 interiorly of the strip ofwrapping material 61 to strengthen the coating being applied undercompression to the tubular member T.

The conveyor system C (FIGS. 1 and 5) includes an inlet conveyor system(FIG. l) and an outlet conveyor system (FIGS. 1 and 5).

A pair of horizontally extending support members or braces 10a and 10b(FIG. 1) extend from the platform P a suitable length to accommodate thelength of at least one tubular member T. The supports 10a and 10b aremounted with suitable bracing or support structure above the ground orfloor or surface to which the apparatus A of the present invention ismounted. An adjustable speed motor 11, which may be powered byelectricity or other suitable energy sources, is mounted with the inletconveyor system 10 and furnishes the power to rotate the tubular memberT while simultaneously moving it longitudinally with respect to theplatform P and placing head H. A drive pulley 11a transfers the energyfrom the motor 11 by a pulley belt 11b to a pulley 11c mounted with adrive shaft 11d. A pulley 11e transfers the energy from the drive shaft11d by a pulley lbelt 11j to a pulley 11g to provide power to rotate andmove the tubular member T. A universal joint 11h transfers therotational movement of the pulley 11g through a drive shaft 11i to drivea suitable gear arrangement 11]l of the well-known type and providerotational movement to a drive pulley 12a of a drive plattform 12.

The drive pulley 12a is mounted to a common axle with a drive wheel 12b,and the axle supporting the drive pulley 12a and the drive wheel 12b issupported by and rotatable within a pair of supports 1.2` which extendupwardly from a movable platform portion 12d of the drive platform 12.The drive wheel 12b has a rubber roller mounted at the periphery thereofto insure a rm and secure mounting of the tubular member T with respectto the drive platform 12 and drive wheel 12b and to provide rotationalmovement while simultaneously moving the tubular member 12longitudinally towards the placing head H.

A pulley belt 12e transfers a portion of the force driving the pulley12a to a second pulley 12j to drive a second drive wheel 12b, alsohaving a rubber wheel mounted to the periphery thereof. The secondpulley 12jc and the second drive wheel 12b are mounted on a common axlewhich is similarly mounted to rotate freely within a pair of upwardlyextending vertical supports 12C which extend upwardly from the movableplatform portion 12d of the drive platform 12.

An arcuate slot 12h is formed in the movable platform 12d extendingtherethrough to permit passage of a bolt or other suitable fasteningmeans 121' which is mounted with the xed portion 12g of the platform 12,in order that the movable platform 12d may rotate with respect to thefixed platform 12g and in conjunction with the groter 1l vQntrQl theSpeed of rQtatiQn Qt the tubular member T as well as the speed oflongitudinal movement of such tubular member T by varying the speed ofthe motor 11 and the placement of the movable platform 12d with respectto the platform 12g and consequently varying the angle of the drivewheels 12b with respect to the longitudinal axis of the tubular memberT.

It should be understood that a number of drive platforms, of likeconstruction to the drive platform 12 set forth hereinabove, may beprovided with the inlet conveyor system 10 and driven by suitabledriving connections by the adjustable speed drive motor 11 in accordancewith the length of the tubular member T to be coated, the desired speedof angular rotation of such tubular member T and the desired speed oflongitudinal movement of the tubular member T With respect t0 theplacing head H.

The outlet conveyor system 15 of the conveyor system C (FIGS. 1 and 5)includes a plurality of horizontally extending rails or braces 15a and15b which extend from the platform P and placing head H on a sideopposite the inlet conveyor system 10 and are mounted to a plurality ofvertical support members 15C and 15d (FIG. 5), respectively, along thelength thereof. The vertical support members 15C and 15d are mountedwith horizontally extending lower support members 15e and 157,respectively, which rest upon a surface 15g on which the apparatus A ismounted.

A plurality of drive belt mountings 16 (FIGS. 1 and 5) are mounted to acorresponding plurality of fixed platform members 16a along the lengthof the rails 15a and 15b for a sufficient length to support the tubularmember T after such member has been Icoated in the placing head H. Thedrive belt mountings 16 support the coated tubular member T and allowaccess to both ends of the coated tubular member T and permit removal ofsuch coated tubular member T from the apparatus A for storage andcuring.

Each of the extractor drive mountings 16 is rotatably movable withrespect to its associated platform 16a by means of a pin 16b mountedwith a movable base platform member 16e.` of such mounting 16 andextending downwardly through an aperture 16d formed in the platform 16a(FIG. 5 A pair of U-shaped supporting brackets 16e are mounted with themovable platform 16C and extend upwardly therefrom. to provide amounting support for a plurality of axles 16g which support a pluralityof drive wheels 16j and a plurality of slave wheels 116,1c (FIG. 5). Theaxles 16g are freely movable with respect to the support bracket 16e toallow rotational movement of the drive wheels 16f and slave wheels 1169cwith respect to the brackets 16e. Driving energy is pro- .vided bysuitable adjustable speed driving means and is furnished by a linkage16h and conveyed through a universal joint to a drive pulley 161' (FIG.l) and a pulley belt 16j (FIGS. l and 5). The pulley belt 16j moves thedrive wheels 16f (FIG. 5) to move an extractor drive belt 16k. The drivebelt 16k rotates the coated tubular member T While simultaneously movingsuch coated tubular member T longitudinally after such member has passedbeneath the placing head H and been compressively coated in a manner tobe set forth hereinbelow.

A variable speed electric motor or other suitable adjustable speeddriving means is provided to drive the linkages 16h and drive pulley161', and such motor is separately controlled from the drive motor 11for reasons that will be more evident herein-below.

The angular placement of the drive belts 16k with respect to thelongitudinal axis of the coated tubular member T as Well as the speed ofmovement of such belt 16k are selectievly varied in the operation of thepresent invention, as will be more evident hereinbelow.

The platform P provides a support for the placing head H and otherassociated equipment, as set forth hereinbelow and includes ahorizontally extending plate 20 of iron, steel, or other suitablematerial, which is mounted with the rails 10A and 10b of the inletconveyor system, 10

and the rails a and 15b of the outlet conveyor system 15. A pair ofmounting brackets or lugs a and 20b (FIG. 1) extend outwardly from theplate 20 in a direction transverse the conveyor system C and havemounted therebetween a mounting rod or -bar 20c, to which are mounted apair of mounting sleeves 20d (FIG. l and 6) and 20e (FIG. l).

The mounting sleeve 20d is movable with respect to the longitudinal axisof the mounting bar 20c to allow a cut-off or removal saw 23 to beselectively positioned at different positions with respect to the lengthof the coated tubular member T passing across the platform P. The cutolfsaw 23 and its associated drive motor 22 are mounted with a mountingplate 21a (FIG. 6) at an upper end of a rotatably movable cut-off arm orsupport arm 21 which is mounted at a lower end to the mounting sleeve20d. The cut-off arm 21 and the mounting sleeve 20d are rotatablymovable with respect to the mounting sleeve 20c (as illustrated by thearrow in FIG. 6) to allow the cut-01T saw 23 to be selectively engagedwith the coated tubular member T and remove by means of an abrasive edge23a thereof the wrapping material 61, the reinforcing wire mesh 62 andthe coating material 82 compressively wrapped with the tubular member T(FIG. 6).

A short portion, for example approximately four inches, of the coatingcompressively wrapped to the tubular member T is removed form the coatedtubular member T in order to provide access for connecting the tubularmember to another tubular member when such members are being installedfor use. lf the tubular member T is an iron or steel pipe, the endportions from which the coating has been removed by the cut-off saw 23are accessible for welding of such tubular members. After welding, thetubular members may be hand packed and have a wrapped material andcovering material applied by hand when such tubular members T are beinginstalled.

The longitudinal movement of the mounting sleeve 20d with respect to themounting rod 20c allows the placement of the saw 23 with respect to thetubular member T to be controlled and adjusted, and the length of theend portion from which the coating and covering materials are removed tobe selectively varied in accordance with the amount of such end portionneeded to be accessible in order to connect the tubular members as theyare being installed, and thus selectively controls the amount of suchaccessible uncovered end portion, and reduces the amount of hand packingrequired when such tubular members T are being installed.

The mounting sleeve 20e (FIG. l) is mounted with the support rod 20C andextends upwardly therefrom, receiving therein a downwardly extendingportion of an L- shaped tubular support arm 25 with which the placinghead H is mounted. The downwardly extending portion of the L-shapedsupport arm 25 is mounted within the upwardly extending mounting sleeve20e (FIG. l) and is rotatable therein in order that an outwardlyextending portion 25a of the support arm 25 with which the placing headH is mounted (FIGS. 1 and 3) may be rotated in order to selectivelyadjust the position of the placing head H with respect to thelongitudinal axis of the tubular member T (FIG. 1). The position of theplacing head H with respect to the tubular member T is varied inaccordance with the diameter of the tubular member T, the thickness ofthe coating material 81 to be applied to the tubular member T, the widthof the strip of reinforcing mesh 62, the rate of longitudinal movementof the tubular member T with respect to the platform P and placing headH, and the speed of rotation of such tubular member T. Suitable means,such as a clamp or brace, are provided to hold the arm 25a and placinghead H firmly in place with respect to the tubular member T duringcoating operations.

An inwardly extending mounting lug 26 (FIG. l) is mounted with theupwardly extending mounting sleeve 20e intermediate the ends thereof,and extends inwardly from the exterior of the platform P towards thetubular member T to provide a support for a bracing wheel 27 (FIGS. 1and 3) which engages an exterior surface 29a of the tubular member T(FIG. 3) and holds such aubular member T firmly in place against theplacing head H while a coating is being applied under compression tosuch tubular member. The bracing wheel 27 is preferably of rubber orother suitable resilient material to provide firm engagement with thetubular member T, and is mounted with an axle 26a in order to be freelyrotatably movable with respect to the mounting lug 26 and roll along theexterior surface 29a of the tubular member T as such tubular member isrotated and simultaneously moved longitudinally with respect to theplacing head H and the coating material S1 and wrapping material 61 andreinforcing mesh 62 are applied under compression to the tubular memberT in the placing head H in a manner to be more evident hereinbelow.

A pair of mounting brackets 31 (FIG. 3) have apertures 31a formedtherein through which the outwardly extending portion 25a of the supportarm 25 may be inserted so that the placing head H may be mounted withthe platform P. A pair of mounting flanges 3lb (FIG. 3) are formed inthe mounting brackets 31 adjacent the apertures 31a, and bolts 31C orother suitable fastening means are inserted through such ange 31h tomount the placing head H with the support arm 25 of the platform P. Theplacing head H may be moved to different positions along the support arm25a in accordance with the diameter of the tubular member T being coatedby the placing head H, and other factors previously set forth. A supportbar or brace 31d is mounted between the brackets 31 to provide furtherstrength for such brackets.

A support member 31e is mounted at one end to an exterior surface 31f(FIG. 3) of the support bracket 31 and extends from the placing head Hin the direction of the storage reels R. A guide bar or rod 31g is`welded or otherwise suitably mounted beneath the support member 31e inorder to guide and properly position the reinforcing wire mesh 62 assuch wire mesh is being conducted from the storage reel R into theplacing head H to be compressively wrapped into the deposited coatingmaterial 81 interiorly of the `wrapping material 61 while such coatingmaterial is being compressively wrapped with the tensioned strip ofwrapping material 61. The position of the guide bar 31g with respect tothe placing head H and tubular member T may be varied to adjust the arcor angle through which the wire 62 travels in the placing head H duringapplication. By moving the guide bar 31g upwardly and inwardly withrespect to the placing head H (FIG. 4), the arc or angle of travel isincreased, increasing the compression of the coating being applied andthereby increasing the weight and strength of such coating on thetubular member T.

The placing head H (FIGS. 1, 3 and 4) is box or chutelike inconfiguration and includes a first of front wall member 32 (FIGS. 3 and4) which is adjacent the front or leading edge of the portion of theexterior surface 29a of the tubular member T currently beingcompressively coated in the placing head T, a second or rear wall member35 (FIG. 3) which is adjacent the rear portion of the exterior surface29a of the tubular member T currently being coated in the placing headI-I, an inner or center Wall member 34 (FIG. 4) which is positionedabove the center of the tubular member T as such tubular member T movesbeneath the placing head H to be coated, and an outer wall 33 (FIGS. 3and 4) which is mounted to the front wall 32 and rear wall 35 oppositethe inner wall 34.

A blade 37 of rubber or other suitable resilient material is mountedwith an upper end 34a of the inner wall member 34 and assists inprevention of splashing or spilling of the coating material 81 as suchcoating material is deposited into the placing head H from the feedchannel L. The lblade 37 is made of a resilient material to allow thefeed channel L and the placing head H to be moved with respect to eachother for cleaning, repair, inspection and like purposes. A second blade37a is mounted with a lower end 34b of the inner wall member 34 andrides and engages the exterior surface 29a of the tubular member T (FIG.4) as such exterior surface moves into position beneath the placing headH and prevents undesired debris and particles from moving the surface29a into the placing head H and further assists in preventing thecoating material 81 from leaking or escaping from beneath the lower end34b of the inner wall member 34.

The rear wall 35 has a blade or funnel member 35a mounted at an upperend 35b adjacent the feed channel L to prevent spillage or escape of thecoating material 81 as such coating material passes and moves into theplacing head H to be deposited onto the exterior surface 29a of thetubular member T. The mounting brackets 31 are mounted with the exteriorof the upper end 35h of the rear wall member 35 of the placing head H.

A lower portion 35C of the rear wall member 35 has a blade 38 of rubberor other suitable resilient material mounted therewith by bolts 35d orother suitable means. The blade 38 and lower portion 35e of the Wallmember 35 have a slight helical taper from an upper end 38a (FIG. 3) ofthe blade 38 to a lower end 38b of such blade, with such taper being inthe direction of rotational movement of the tubular member T withrespect to the placing head H, in this embodiment clockwise (FIG. 4).The slight helical taper of the blade and wall portion 35C provides achanneling or funneling action and convey and assist in compacting thecoating material 81 being deposited onto the tubular member T in theplacing head H.

The front wall member 32 is mounted along an edge with the inner wallmember 34 and has a slight helical taper from an upper end 32a to alower end 3211 in a direction opposite the direction of rotation of thetubular member T to provide a further channeling and funnelingcompacting action with respect to the coating material 81 beingdeposited onto the tubular member T in the placing head H.

The outer Wall member 33 is pivotally mounted at an upper end 33abetween the lower wall portion 35a` of the rear wall member 35 and thelower portion 32b of the front wall 32. Outer wall member 33 is pivotedinwardly to a work position (shown in phantom in FIG. 4) to support thecoating material 81, wrapping material 61 and reinforcing mesh 62 assuch materials are applied to the tubular member T. The spacing of theWall member 33 with respect to the tubular member T when the wall member33 is pivoted inwardly to the work position determines the thickness ofthe coating to be applied by the placing head H.

A bar or block 33b of metal or other suitable material is mounted at alower end 33a of the wall member 33 adjacent the rear wall member 35.When the outer wall member 33 is pivoted inwardly to the work position,the bar 33b engages the reinforcing mesh 62 to the desired depth in thecoating material 81 and displaces the coating material 81 inwardly withrespect to the tubular member T. 'Ihe inward displacement of the coatingmaterial by the bar 33b forms a shoulder (FIG. 4A) at the trailing edgeof the coating being applied to the tubular member T in order to form anoverlap of reinforcing mesh 62 within the coating applied to the tubularmember T.

A vibrator 39, or other suitable means for introducing motion, ismounted with the outer Wall member 33 and is energized by an air pump orother suitable motor through a conduit 39a to vibrate the placing headH, causing a compacting and vibrating force to be applied to the coatingmaterial 81 within the placing head H being deposited onto the tubularmember to cause the coating material 81 to be rm and substantiallyuniform in composition while auch material is being compressivelywrapped against the tubular member T. The uniform composition of thecoating material 81 and compressive application of such, as will be setforth hereinbelow, obtain consistent density and absrption in thecoating material 81, eliminating porosity therein `and providing evenlycoated, smooth tubular members T of increased strength. The firmness ofthe deposited coating material 81 eliminates the likelihood that thecoated tubular members T require curing, permitting earlier handling,installation and use of the coated members T.

An angle iron member 33d, or other suitable structural member, isattached to the lower portion 35e of the rear wall member 35, the outerwall member 33, and the lower portion 32h of the front wall member 32 tostrengthen the placing head H against the vibratory forces induced insuch placing head by the vibrator 3-9, and to limit pivotal movement ofthe outer wall member 33.

A guide roller 41 (FIGS. 3 and 4) which is rotatably movable withrespect to the lower portion 35e of the wall member 35 and the lowerportion 32b of the front Wall member 32 is mounted between such Wallmembers and guides and conducts the strip of wrapping material 61 fromthe reels R where such material is held in tension, as will be moreevident hereinbelow, into the placing head H in order that the wrappingmaterial `61 may compressively wrap the coating material 81 against thetubular member T within such placing head H.

A pair of plates 42a and 42b are mounted with the upper portion 35b ofthe rear Wall member 35 and the upper portion 32a of the front wall 32and extend therebetween to form a guide chute for the strip ofreinforcing mesh 62 being compressively wrapped into the depositedcoating 81 interiorly of the wrapping material 61 in the placing head H.A pair of metal rods 43a and 43b are similarly mounted between the wallmembers 32 and 35 and form a pair of guide bars for the strip ofreinforcing mesh 62 to further assist in maintaining such strip of meshin proper position while such strip of mesh is being compressivelywrapped into the deposited coating 8 1 in the placing head H.

A bar or rod 44 (FIG. l) is mounted to a frame or other suitablestructure (not shown) at an elevated position with respect to the guidebar 31g and conveys and guides the strip of wrapping material 61 and thestrip of reinforcing mesh 62 across such bar 44. Suitable spacing rodsor other structure are provided to insure that the reinforcing mesh 62and the covering material 61 are maintained spaced with respect to eachother as such pass over the bar 44. The bar 44 is elevated with respectto the reels R and th'e placing head H to assist in conducting thereinforcing mesh 62 and wrapping material 61 under tension from thereels R to the placing head H in order that the wrapping material 61 andreinforcing mesh 62 may compressively wrap the deposited coatingmaterial 81 against the exterior surface 29a of the tubular member T.

Each of the storage reels R (FIG. 1) include an upwardly extending atmetal plate 51 which is mounted with a frame member 52 to a supportmember S3. The support member 53 is mounted with a post 54, the top ofwhich is shown (FIG. l), above the ground or surface on which theapparatus A is mounted. An axle 55 is centrally mounted with respect tothe plate 51 and extends outwardly therefrom. A reel or roll of wrappingmaterial 61 is mounted on the axle 55 adjacent the metal plate 51 on arst storage reel R-l and a reel of reinforcing mesh 62 is mounted in alike manner to a second storage reel R-2.

An outer plate 56 is mounted onto the axle 55 exteriorly of the plate 51on the reel R-l containing the wrapping material 61 and the reel R-2containing the reinforcing mesh 62 and is selectively compressed againstthe reel mounted thereon by adjusting the tension placed against theplate 56 by a nut 57 or other suitable means threaded onto the exteriorQ15 the axle 55.

An arm 56a is mounted with each plate 56 and is engaged against thesurface adjacent the reels R-l and R-Z by initial rotational movement ofsuch reels and is forced into engagement against such surface duringfurther rtational movement of such reels to further assist in providinga tensile force on the reinforcing mesh 62 and wrapping material 61 assuch materials are conducted from the reels R into the placing head H tobe compressively wrapped onto the tubular member T and compress thecoating material 81 against such tubular member. Additional axles S andmetal plates 51 are provided for storage of additional reels of wrappingmaterial and reinforcing mesh to be used in the coating operations ofthe present invention.

An additional support arm 45' (FIG. 1) is mounted at an elevatedposition adjacent the rearmost reel R-2 containing the reinforcing mesh62 and conducts such reinforcing mesh to a position elevated withrespect to the reel R-l containing the wrapping material 61 to preventthe mesh 62 from contacting the wrapping material 61 and tearing such,as such materials are conducted from the reels R into the placing headH. i

The amount of tension applied to the reinforcing mesh 62 and thewrapping material 61 by the reels R in order to position the reinforcingmesh at the desired radial relationship within the coating, and thedesired tensioning of the nut 57 with the axle 55 to achieve suchtension are selectively varied in accordance with the speed of rotationand longitudinal movement of the tubular member T, the thickness ofcoating material 81 being deposited thereon, the desired position of thereinforcing mesh 62 within the coating 81, and the amount of compressiveforce to be applied to the coating 81 by the wrapping material 61.

The coating material conveyor belt system S (FIGS. 1 and 5) includes anendless conveyor belt 70 of the well known type which conveys the dryconstituents of the coating material, in this embodiment cement andgravel, from a position, adjacent storage hoppers of the well knowntype, at which the cement and gravel are deposited onto a lower end ofthe belts 70 and transported by such belt 70 to an upper end 70a (FIGS.1 and 5).

The ldry constituent materials of the coating material 81 are depositedfrom the upper end 70a of the belts 70 into a funnel shaped upper end71a (FIG. 5) of an inlet tube or conduit 71 and fall and pass throughsuch conduit 71 into the mixing chamber M. The tube 71 is mounted at alower end 71b to the mixing chamber M and supported by such mixingchamber.

A plurality of angle iron members 73 are each inserted through L-shapedapertures on diametrically opposed sides of th'e tube 71 and extendthrough the interior of the tube 71 in a helical or revolving pattern inorder to mix and intermingle the dry constituents of the coatingmaterial as such constituents fall and pass through the tube 71 to themixing chamber M.

The mixed and intermingled dry constituents of the coating material passthrough the lower end 71b of the tube 71 and an opening in a top member7 5a of the mixing chamber M into a chamber 78 of the mixing chamber Mformed by a cylindrical wall member 75b (FIGS. l and 5) and afrusto-conical shaped lower wall member 75C.

Liquid, in this embodiment water, is added to the dry constituents ofthe coating material in the chamber 78 of the mixing chamber M by beingsprayed from a plurality of apertures 77a formed in the interior of anannular ring or pipe 77 mounted within the chamber '78. An outletconduit 6a conveys the liquid to be added to the dry constituents of thecoating material in the mixing chamber M to such mixing chamber, and avalve 6b controls and regulates the flow of such liquid from the inletconduit 87a t0 the annular spray ring 77 in the chamber 78 in order toselectively control and regulate the mixture of the liquid and the dryconstituents being mixed in the chamber 78.

By adding liquid to the dry constituents in the mixing chamber aftersuch constituents have been conveyed from their respective storagehoppers, rather than conveying the mixed material on conveyor belts, theamount of mixed coating material is kept to a small amount. Thus in theevent of equipment stoppage or malfunctioning, the number of parts ofthe apparatus A from which the coating material must be removed beforeit hardens and the amount of coating material to be removed, is kept toa minimum reducing loss and waste of such coating material.

The constituents of the coating material fall through an opening 75b inthe mixing chamber M into the feed chamber L after the liquid is addedin the chamber 78. To assist movement of the coating material throughthe feed channel L, the mixing chamber M is mounted on suitable supportsat a slightly higher elevation than the upper or inlet end of theplacing head H.

The feeed channel L includes a U-shaped or semicircular shaped conveyorchannel S0 which extends from an inlet end a (FIG. l) beneath the mixchamber M to an outlet end 80b adjacent the open upper end of theplacing head H (FIGS. 1 and 3). A pair of upwardly extending arms orflanges 80C are formed extending up wardly from the channel member 80 atthe inlet 80a to enclose the opening 75d in the mix chamber M andprevent spillage and waste of the coating material 81 as such coatingmaterial passes from the chamber 78 into the feed channel L.

A metering auger or screw conveyor 83 transports and mixes the coatingmaterial from the inlet end 80a of the feed channel 80 to the outlet end80h adjacent the placing head H. A motor 84 which is mounted with aplatform 85a beneath the channel member 80 by a plurality of mountingarms 85b or other suitable mounting means provides the power to drivethe metering auger 83 by means of a pulley belt 84a driving a pulley 84band rotating such pulley to rotate the metering auger 83. The motor 84is of the Well-known type whose speed is adjustably controllably inorder that the speed of rotation of the metering auger 83 may beselectively controlled to control the thickness of the coating materialbeing conveyed and mixed by the metering auger 83 and being deposited bythe placing head H onto the tubular member T, as Well as to control theamount of such coating material being deposited onto the tubular memberT.

In the operation of the present invention, the tubular member T isplaced on the inlet conveyor system 10 and rotated and movedsimultaneously longitudinally with respect to its longitudinal axis bymeans of the roller wheels 12b on the platforms 12 until a first end ofsuch tubular member is adjacent the placing head H.

The dry constituents of the coating material 81 are conveyed by the belt70 and deposited through the tube 71 into the mixing chamber M where theliquid constituents of such coating material are added, and the coatingmaterial 81 is thus formed in the mixing chamber M.

The coating material 81 after being formed in the mixing chamber M ismoved by the metering auger 83 through the feed channel L whilesimultaneously being mixed by such metering auge'r 83. At the outlet end80b of the feed channel L the coating material 81 passes into the openupper end of the placing head H (FIG. 4) and is deposited by the placinghead H onto the tubular member T. By depositing the coating material 81directly onto the tubular member T, the likelihood of snags, rips Jrtears to the strip of covering material 61 is reduced, and a moreacceptable and longer lasting coated tubular member T is thus formed inthe method and apparatus of the present invention. Further, damage tothe protective coating on the exterior surface 29a of the tubular memberT is prevented.

An initial wrap of coating mterial 81 is applied to the exterior surface29a of the tubular member T, and the strip of reinforcing mesh 62 andthestrip of wrapping material 61 are conducted from their respectivestorage reels R-Z and R-l to the initial wrap of coating material 81 andapplied with such coating material 81 to the tubular member T. Thewrapping material 61 and reinforcing mesh 62 are passed through theplacing head H as the initial hand wrapping of the tubular member Ttakes place.

After applying an initial wrap for one revolution of the tubular memberT, the coating material 81 in the placing head H is deposited onto thetubular member, and the tubular member T is rotated and movedlongitudinally with respect to the placing head H by the inlet conveyorsystem 10. Tension is maintained in the strip of the wrapping material61 and the strip of reinforcing mesh 62 by the hand-applied initial wrappulling against the tension maintained in the storage reels R by thetightened nut 57 and the outer plate 56 as the tubular member T is beingrotated and simultaneously moved longitudinally with respect to itslongitudinal axis by the inlet conveyor system 10.

The tension in the strip of wrapping material 61 and the strip ofreinforcing mesh 62 compresses the coating material 81 against theexterior surface 29a of the tubular member T as such tubular member isrotating and moving longitudinally past the placing head H, and thus thecoating being applied to the tubular member T in the method andapparatus of the present invention is applied under compression to suchtubular member to strengthen and increase the service life of thetubular member T.

The tension in the wrapping material 61 and the compressive wrapping ofthe coating material 81 with the tubular member T allow use of largeraggregate in the concrete, permitting use of less cement to obtain thesame strength concrete coating. The tension and compressive wrappingalso obtain improved adhesion between the coating material 61 and theuncoated or protective coated exterior surface 29a of the tubular memberT, as well as allow coating of tubular members of small diameters.

The inlet conveyor system continues the rotating and longitudinalmovement of the tubular member T past the placing head H, and thecoating material 81 deposited onto the tubular member T is compressivelywrapped by the Wrapping material 61 and reinforcing mesh 62 against theexterior surface 29a of the tubular member T, forming a helical spiralwrap of such coating, reinforcing mesh and covering material about thetubular member T (FIG. 2).

As the application of the coating to the tubular member T proceeds, thebelts 16k on the outlet conveyor system transport and support the coatedportion of the tubular member T away from the placing head H. The belts16k and the outlet conveyor systems 15 move at a slower speed than thedrive wheels 12b in the inlet conveyor system 10 to equalize the torqueon the tubular member T, since the coated portion of the tubular memberT is larger in diameter than the uncoated portion.

As the trailing end of the tubular member T currently being coated inthe placing head H approaches the placing head H, a second tubularmember T is mounted with the inlet conveyor system 10 and conveyed bysuch conveyor system into position such that the leading end of thesecond tubular member abuts the trailing end of the rst tubular memberT. As the abutting end portions of the two tubular members pass beneaththe placing head, coating operations continue uninterrupted as coatingof the iirst tubular member is completed and the coating of the secondtubular member is begun, allowing increased eiciency and greateroperating speed when coating such tubular members.

After the abutting end portions have been coated, the end portions passfrom beneath the placing head H to a position adjacent the cut-off sawblade 23. The cut-olf arm 21 is then pivoted inwardly until the abrasiveedge 23a of the saw blade 23 comes into contact with the coating appliedt0 the irst tubular member at a position,

for example four inches, slightly in advance of the abutting endportions, and the motor 22 is energized so that the abrasive edge 23a ofthe saw blade 23 may cut through the covering material 61, thereinforcing wire mesh 62 and the coating material 81 to reach theexterior surface 29a of the tubular member T. Any residue of coatingmaterial clinging to the tubular member T and not removed by the saw 23may be washed or hosed oif, if desired. Such cutting action removes thecoating applied to the tubular member T from an end portion of thetubular member, and provides access to the tubular member T for weldingor other installing operations as such tubular members are beinginstalled. The cut-off arm 21 is movable longitudinally along themounting bar 20c to allow the amounts of coating material removed by thecut off blade 23 to be controlled in order to reduce to a minimum theamount of tubular member T left exposed, thereby reducing the amount ofhandpacking or wrapping required when installing such tubular members.

In a like manner, the coating applied to the leading edge of the secondtubular member abutting the trailing edge of the rst tubular memberl isremoved to provide access to such tubular member for installation. Thecontinuous coating of abutting end portions of tubular members as a rsttubular member is completing being coated and a second tubular member isto begin being coated, with subsequent removal of portions of thecoating material, allows continuous operation and eliminates therequirements of having to hand wrap the leading and trailing endportions of each tubular member as such tubular member is being coatedin the apparatus, in addition to reducing the amount of tubular member Tleft bare during coating operations.

After the coating has been removed from the abutting end portions of thetwo tubular members, the iirst tubular member T is in condition forremoval from the coating apparatus A in order to be stored to cure thecoating applied to such tubular member. The speed of the belt 16k in theoutlet conveyor system 15 is increased in order to increase thelongitudinal movement of the rst tubular member which has beencompleted, and thus move the first tubular member away from the secondtubular member which is currently being coated in the placing head H.Movement of the coated tubular member T away from the member beingcoated provides access to the ends of coated tubular member T to allowthe coated tubular member T to be removed from the outlet conveyorsystem 15 by a crane, or other suitable removing means to be stored orstacked or to be transported to a location for installation and use.When being installed for use, the smooth exterior coating of the tubularmembers T pass over the rollers of the installing equipment withoutdamaging such installing equipment.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape and materials as well as in the details of the illustratedconstruction may be made Without departing from the spirit of theinvention.

What is claimed is:

1. An apparatus for applying a coating under compression to a tubularmember which is being rotated and moved along its longitudinal axisadjacent the apparatus, comprising:

(a) conveyor means for rotating said tubular member and moving saidtubular member along its longitudinal axis;

(b) a support frame positioned adjacent said conveyor means;

(c) reel means for storing a roll of wrapping material;

(d) placing head means mounted with said support frame, said placinghead means including:

(1) a first wall member;

(2) a second wall member spaced from said rst wall member;

(3) means for depositing a coating material onto the rotating tubularmember between said rst and second wall members;

(4) an outer wall member pivotally mounted with said first Wall memberand said second wall member and movable relative thereto to a positionto determine the thickness of the coating material deposited onto thethe roating tubular member by said placing head means;

(5) means for compressively wrapping the deposited coating materialagainst the rotating tubular member with a strip of the Wrappingmaterial substantially simultaneously With the depositing of saidcoating material to form a covered coating layer on the tubular member;and

(e) means for conducting the strip of wrapping material under tension tothe placing head from said reel means whereby the tension in the stripof Wrapping material compresses the coating material against tubularmember.

2. The structure of claim 1 further including:

(a) a second reel means for storing a roll of reinforcing wire mesh; and

(b) said placing head means further includes means for compressivelywrapping a strip of the roll of reinforcing wire mesh into the depositedcoating interiorly of the wrapping material to strengthen the coating.

3. The apparatus of claim 1 wherein said placing head means furtherincludes:

vibrator means for eompacting the coating material in the placing headWhile depositing such coating material onto the tubular member, whereina substantially uniform composition of coating material is applied tothe tubular member.

4. The apparatus of claim 1, further including:

(a) means for storing the dry constituents of the coating material;

(b) means for conveying the required amount of dry constituents of thecoating material to a mixing station adjacent the placing head;

(e) mixing chamber means at said mixing station adjacent said placinghead receiving the dry constituents from said conveying means for addingliquid to the dry constituents to form the coating material whereby onlyrequired amounts of such coating material are mixed as needed therebyreducing waste of such material when coating operations are unexpectedlyinterrupted; and

(d) means for further mixing and conveying said coating material fromsaid mixing station to said placing head means.

References Cited UNITED STATES PATENTS 2,945,278 7/ 1960 Robertson 25-382,368,742 2/1945 Brend 91-14 1,961,974 6/1934 Kramer 138-175 2,269,0321/1942 Moore 25-38 2,696,353 12/1954 Vessels 118-320 X 2,470,068 5/ 1949Contenson 25-38 3,190,780 6/1965 McNulty etal. 156-392 X 3,245,856 4/1966 Morain 156-392 X DANIEL I. FRITSCH, Primary Examiner U.S. Cl. XR,

